ABSTRACTAround the globe there is a demand for the development of bio-based lubricants that are biodegradable, non-toxic, and environmentally friendly. This paper outlines the friction and wear characteristics of pongamia biodiesel contaminated bio-lubricant using a pin-on-disc tribometer. To formulate the bio-lubricants, pongamia oil-based biodiesel was blended in ratios of 5, 10, and 20% by volume with the base lubricant SAE 20W40. The tribological characteristics of these blends were carried out at 2.5 m/s sliding velocity and the loads applied were 50, 100, and 150 N. Experimental results showed that the lubrication regime present during the test was boundary lubrication, while the main wear mechanism was adhesive wear. During testing, the least wear was found with the addition of 5 and 10% pongamia oil-based biodiesel, and above this level of contamination the wear rate increased considerably. The addition of 5 and 10% pongamia oil-based biodiesel with the base lubricant represents a very good lubric...